﻿// --------------------------------------------------------------------------------------------------------------------- 
// <copyright file="NullValues.cs" company="Scrum for Team System">
//   None
// </copyright>
// <summary>
//   Defines the NullValues type.
// </summary>
// ---------------------------------------------------------------------------------------------------------------------
namespace ScrumForTeamSystem.Metrics
{
    /// <summary>
    /// Defines the NullValues type.
    /// </summary>
    internal class NullValues : ModelBase
    {
        /// <summary>
        /// Gets a single point on the Trend line. Null is returned if the Trend line is not to be drawn for this position.
        /// </summary>
        /// <returns>
        /// A null value.
        /// </returns>
        public override double? GetNextTrendValue()
        {
            return null;
        }

        /// <summary>
        /// Overridden in subclasses to calculate a Trend line.
        /// </summary>
        protected override void CalculateTrend()
        {
            // Nothing to do.
        }
    }
}
